Frontiers in Bioengineering and Biotechnology
·
2020
·
IF 3.644
Peng Fei,Su Hui-Hui,Ou Xiao-Yang,Ni Zi-Fu,Zong Min-Hua,Lou Wen-Yong
(R)-1-phenyl-1,2-ethanediol is an important synthon for the preparation of β-adrenergic blocking agents. This study identified a (2R,3R)-butanediol dehydrogenase (KgBDH) from Kurthia gibsonii SC0312, which showed high enantioselectivity for production of (R)-1-phenyl-1,2-ethanediol by reduction of 2-hydroxyacetophenone. KgBDH was expressed in a recombinant engineered strain, purified, and characterized. It showed good catalytic activity at pH 6–8 and better stability in alkaline (pH 7.5–8) than an acidic environment (pH 6.0–7.0), providing approximately 73 and 88% of residual activity after 96 h at pH 7.5 and 8.0, respectively. The maximum catalytic activity was obtained at 45°C; nevertheless, poor thermal stability was observed at >30°C. Additionally, the examined metal ions did not activate the catalytic activity of KgBDH. A recombinant Escherichia coli strain coexpressing KgBDH and glucose dehydrogenase (GHD) was constructed and immobilized via entrapment with a mixture of activated carbon and calcium alginate via entrapment. The immobilized cells had 1.8-fold higher catalytic activity than that of cells immobilized by calcium alginate alone. The maximum catalytic activity of the immobilized cells was achieved at pH 7.5, and favorable pH stability was observed at pH 6.0–9.0. Moreover, the immobilized cells showed favorable thermal stability at 25–30°C and better operational stability than free cells, retaining approximately 55% of the initial catalytic activity after four cycles. Finally, 81% yields (195 mM product) and >99% enantiomeric excess (ee) of (R)-1-phenyl-1,2-ethanediol were produced within 12 h through a fed-batch strategy with the immobilized cells (25 mg/ml wet cells) at 35°C and 180 rpm, with a productivity of approximately 54 g/L per day.
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PubMed
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 19
·3624
·
IF 3.06
Guangyun Wang,Tiezheng Wang,Yuanyuan Zhang,Fang Li,Boyang Yu,Junping Kou
The neuroprotective role of schizandrin (SA) in cerebral ischemia-reperfusion (I/R) was recently highlighted. However, whether SA plays a regulatory role on autophagy in cerebral I/R injury is still unclear. This study aimed to explore whether the neuroprotective mechanisms of SA were linked to its regulation of AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/autophagy pathway in vivo and in vitro. The present study confirmed that SA significantly improved oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced PC12 cells injury. The results of immunoblotting and confocal microscope showed that SA decreased autophagy in OGD/R-injured PC12 cells, which was reflected by the decreased Beclin-1 and LC3-II expression, autophagy flux level, and LC3 puncta formation. In addition, the autophagy inducer rapamycin partially prevented the effects of SA on cell viability and autophagy after OGD/R, whereas the autophagy inhibitor 3-methyladenine (3-MA) exerted the opposite effect. The results of Western blotting showed that SA markedly decreased the phosphorylation of AMPK (p-AMPK), whereas the phosphor-mTOR (p-mTOR) levels increased in the presence of OGD/R insult. Furthermore, pretreatment with the AMPK inducer AICAR partially reversed the protective effects and autophagy inhibition of SA. However, AMPK inhibitor Compound C pretreatment further promoted the inhibition of SA on autophagy induction and cell damage induced by OGD/R. Taken together, these findings demonstrate that SA protects against OGD/R insult by inhibiting autophagy through the regulation of the AMPK-mTOR pathway and that SA may have therapeutic value for protecting neurons from cerebral ischemia.Keywords:OGD/R;autophagy;AMPK/mTOR;schizandrin;ischemic stroke
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高影响因子
PROCESS BIOCHEMISTRY
·
2019
·
IF 2.883
Xinyun Xu,Jiahao Wang,Ting Yu,Haohan Nian,Hui Zhang,Guangli Wang,Feng Li
Aryloxyphenoxypropionate (AOPP) herbicides with a chiral center are widely used to selectively remove annual and perennial grasses. However, the study of the enzymes involved in enantioselective degradation of AOPP herbicides is limited. A novel family VIII carboxylesterase gene, estwx , hydrolyzed the ester bond cleavage of AOPP herbicides to form the corresponding acid and alkyl side chain alcohol, was cloned from Brevundimonas sp. strain QPT-2 and overexpressed in E. coli BL21. The purified recombinant EstWX was shown to hydrolyze a wide range of AOPP herbicides with various catalytic efficiencies. The enantioselectivity assay indicated that EstWX preferentially catalyzed the hydrolysis of the R -enantiomer of AOPP herbicides. The S73, K76, Y196 together with W368 residues, especially S73 and Y196, were essential for the catalytic function of the carboxylesterase. EstWX is a promising candidate for the bioremediation of multiple AOPP herbicide-contaminated environments and for future mechanism studies on the enantioselective degradation of chiral AOPP herbicides.
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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2025
·
IF 4.6
Kai Wang,Yan-Ru Wang,Jun Zhao,Ren-Min Zhou,Xi-Feng Xu,Tong Wang,Zhong-Yuan Cheng
Hepatic ischemia-reperfusion (I/R) injury is a major clinical complication, and the precise monitoring of key inflammatory mediators like neutrophil elastase (NE) in vivo remains a significant challenge. To address this, we developed HDS-NE, a highly specific and activatable molecular probe based on a sulfur-substituted hemicyanine scaffold, engineered for the simultaneous detection of NE via fluorescence and photoacoustic imaging modalities. The probe demonstrated exceptional sensitivity and selectivity toward NE, enabling the real-time visualization of elevated NE activity in a murine model of hepatic I/R injury. Both in vivo and ex vivo imaging results confirmed a markedly enhanced signal in injured livers compared to controls, which was further validated by serum assays and histology. Crucially, this study represents the successful achievement of non-invasive, in vivo imaging of NE activity during hepatic I/R processes, offering a powerful tool for diagnosing and studying inflammatory liver diseases.
研究领域:
分子影像学
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炎症研究
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肝脏病学
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生物医学工程
·
光学成像
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PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 5
·2134-2142
·
IF 3.784
Yafei Liu,Zhilong Fu,Xingyu Chen,Yaxin Wei,Bo Zhang,Aimin Chang
Rare-earth ions doped Ca 0.9 R 0.1 CeNbMoO 8 ( R = Y, Sm, Nd, La) ceramics have been successfully prepared by solid-state method, and their modifications to the microstructure and electrical properties are also investigated. The rare-earth ions doped ceramics exhibit the scheelite structure. With the increase in the radius of rare-earth ions, the lattice distortion and bond interaction will be enhanced, and the consistency of grain size will be reduced. The ceramics exhibit negative temperature coefficient (NTC) thermistor characteristics in the temperature range of 473 K-1273 K, and the activation energy decreases with the increase of the radius of rare-earth ions. Rare-earth ions doping can increase the content of Ce 3+ ions and promote the conductivity of ceramics. Except for Sm 3+ -doped ceramics, the high-temperature aging rate of other ceramics is less than 2%. The existence of some metastable Sm 2+ ions in Sm 3+ -doped ceramics not only increases the activation energy, but also reduces the high-temperature stability of the ceramics.
研究领域:
材料科学
·
固态物理
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高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Ying Zhang,Zhi-Wen Duan,Han-Yu Liu,Feng Qian,Pu Wang
Microbial whole-cell catalysis has been a popular method for chiral alcohols preparation. In this study, Cyberlindnera saturnus ZJPH1807 was successfully employed as a biocatalyst to reduce 2-chloro-1-(2,4-dichlorophenyl)ethanone (CPE) to ( R )-2-chloro-1-(2,4-dichlorophenyl)ethanol (( R )-CPEO), a key chiral intermediate of antifungal drug miconazole. In order to further improve the bioprocess yield, natural deep eutectic solvent and cyclodextrin were introduced into the reaction system as additives. It was found that carnitine/trehalose (C/Tre, 1:1 mol/mol) could increase the permeability of cell membrane appropriately and improve the mass transfer rate. And the addition of methyl-β-cyclodextrin (MCD) could improve the solubility of CPE in buffer solution, simultaneously promoting cofactor recycling. Furthermore, MCD and C/Tre exerted a synergistic effect on the acceleration of CPE bioreduction, producing 91.0% yield in 1.5 h at 35.8 mM CPE in a C/Tre-MCD-containing system, with a 12.4-fold increase in productivity compared to neat buffer solution only. When the substrate loading was increased to 67.1 mM, the yield could also achieve 84.2%. The established bioreduction process was also feasible at 100 mL preparation scale with a 88.5% ( R )-CPEO yield. The integration of C/Tre and MCD can significantly improve catalytic efficiency for hydrophobic substrates and be applied in biocatalysis.
研究领域:
生物化学
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微生物学
·
制药工程
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高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Yibo Zhang,Shen Wang,Biao Liu,Yan Hao
MgAl 2 O 4 :Cr 3+ transparent ceramics were prepared by a hot-pressed sintering process with Y 2 O 3 and La 2 O 3 as sintering aids, and the effects on the microstructure, densification, optical transmission, and photoluminescent properties were investigated. The sintering aids of Y 2 O 3 and La 2 O 3 enhanced the relative density, reaching 99.33% with 2.4 wt% Y 2 O 3 and 99.24% with 0.8 wt% La 2 O 3 . La 2 O 3 also inhibited abnormal grain growth and obtained ceramics with uniform grain size. In addition, the optical transmission was also improved with Y 2 O 3 and La 2 O 3 as sintering aids. The transmission of the ceramic with 2.4 wt% Y 2 O 3 exceeded 78% in the region of 700–6000 nm and reached 83% at 1450 nm. Moreover, Y 2 O 3 and La 2 O 3 both contributed to improving the quantum yield of the ceramics, especially for Y 2 O 3 , and the quantum yield was about 0.354, which was approximately two times higher than that without R 2 O 3 . In summary, La 2 O 3 was helpful for improving sintering process, inhibiting grain growth, and homogenizing the grain size, while Y 2 O 3 was significant for enhancing the optical and photoluminescent properties.
研究领域:
材料科学
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无机非金属材料
·
功能陶瓷
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光电子学
·
固态发光材料
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高影响因子
BIOTECHNOLOGY AND BIOENGINEERING
·
2026
·
IF 3.9
Teng-Kun Huang,Cen Huang,Du Wu,Shuang Li,Ren-Chao Zheng,Xiao-Ling Tang,Yu-Guo Zheng
( R )-3-Aminobutanol is a valuable chiral amino alcohol widely used in the pharmaceutical industry. The amine dehydrogenase (AmDH)-catalyzed synthesis with inorganic ammonia as the amine donor represents one of the most promising routes for its production. However, this approach is limited by the low catalytic efficiency of AmDHs toward the unnatural substrate 4-hydroxy-2-butanone, as well as the high cost associated with coenzyme requirements. To address these issues, a structure-guided engineering strategy integrating loop remodeling with dynamically coupled network analysis was employed to modify an AmDH derived from leucine dehydrogenase ( GKGB -AmDH). A pentamutant was obtained with a 7.8-fold increase in catalytic efficiency ( k cat / K m ) and a 6.8-fold increase in specific activity. Molecular dynamics simulations were performed to elucidate the molecular mechanism underlying the improved catalytic performance. A dual − enzyme co-expression system for GKGB -AmDH-M5 and formate dehydrogenase (FDH) was established for in situ NADH regeneration. As a result, the catalytic efficiency toward 4-hydroxy-2-butanone was enhanced, and the conversion reached 83.8% at a substrate concentration of 300 mM, with an enantiomeric excess ( e.e .) of > 99.99%. These results demonstrate the feasibility of this engineering strategy and provide a theoretical basis for the efficient and green biomanufacturing of chiral amino alcohols.
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高影响因子
iScience
·
2025
·
IF 4.1
Hechen Shen,Xu Bao,Bingcai Qi,Xiaoyu Liang,Yun Chang,Xiaomin Hu,Wenqing Gao,Di Sun
Myocardial infarction (MI) poses a severe threat to human life, and timely reperfusion of ischemic myocardium stands as the most effective treatment approach. However, myocardial ischemia-reperfusion (I/R) could lead to the excessive generation of reactive oxygen species (ROS), worsening myocardial injury. In this investigation, a ROS-responsive injectable hydrogel encapsulating melatonin (MLT) was synthesized. This hydrogel could provide a controlled release of MLT, markedly enhancing its antioxidant, anti-inflammatory, anti-apoptotic, and autophagy-modulating effects, thereby significantly mitigating myocardial ischemia-reperfusion injury (MIRI). Moreover, this study proposes an injection method of ultrasound delivery, which offers significant advantages to MI patients without the necessity of thoracotomy In conclusion, This ROS-responsive hydrogel loaded with MLT established the basis for minimally invasive treatment of myocardial I/R injury, which has considerable potential for the treatment of MIRI.
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高影响因子
CURRENT NEUROVASCULAR RESEARCH
·
2025
·Vol. 22
·期 1
·70-85
·
IF 1.7
Ziteng Yang,Yuanqi Zuo,Guangyun Wang,Ning Wang
Introduction: The endothelial barrier is composed of brain microvascular endothelial cells (BMECs) and tight junction (TJ) proteins. Musk is a valuable ingredient in Traditional Chinese Medicine (TCM). It is used in the treatment of stroke because of its ability to induce resuscitation. The core component of musk is muscone. Previous studies have evidenced that muscone may be involved in the treatment of ischemic stroke (IS), but the underlying mechanism is still unclear. The main objective of this study was to explore the protective effect of muscone on OGD/R-induced endothelial barrier disruption and determine its underlying mechanism. Methods: OGD/R-induced damage to BMECs was assessed using the MTT and LDH assays. The apoptosis level in BMECs was determined using western blot and Hoechst staining. Western blot, immunofluorescence, and phalloidin staining were used to assess the expressions of TJ proteins and pathway proteins expression. A monolayer cell barrier was constructed using BMECs in vitro, and the permeability of the barrier was assessed by TEER as well as the transmissivity of sodium fluorescein. Molecular docking, DARTS, and CETSA were used to verify the regulatory effect of muscone on the pathway. Results: Muscone reduced OGD/R-induced apoptosis of BMEC cells, inhibited the degradation of TJ proteins, promoted the coherent expression of ZO-1 on the membrane, and restored TEER. Mechanistic studies showed that H-89 reversed the promoting effects of muscone on pathway proteins and promoted the disassembly of the actin cytoskeleton, which, in turn, promotes BMEC apoptosis and TJ protein degradation, ultimately disrupting the endothelial barrier. Discussion: The inhibition of BMEC apoptosis and improvement of endothelial barrier damage by muscone may be an important mechanism for treating ischemic stroke. Conclusion: We demonstrated that muscone could reduce OGD/R-induced hyperpermeability of the brain endothelial barrier by activating the PKA/RHOA/MLC pathway.
研究领域:
神经科学
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药理学
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中医中药
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细胞生物学
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分子生物学
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PubMed
高影响因子
ISME Journal
·
2025
·
IF 10
Yan Baofei,Zheng Xian,Lu Danya,Li Ting,Chen Xi,Shao Zhitao,Fu Tingming
Microbiota-associated factors are increasingly recognized as significant contributors to the progression of ulcerative colitis, and microbial modulation has emerged as an effective therapy for this condition. The herbal compound silibinin has demonstrated properties that modulate gut microbiota. Herein, we investigated the response of gut microbiota to silibinin in ameliorating colitis, using a mouse model of colitis coupled with antibiotic exposure. Results indicated that antibiotic pretreatment negated the benefits of silibinin in mice with colitis. Furthermore, fecal microbiota transplantation involving silibinin-modulated gut microbiota further substantiated the gut microbiota-dependent effects of silibinin. Within the metabolic profiles of silibinin-regulated microbiota, we identified that Alistipes-associated (R)-2,3-dihydroxy-isovalerate exhibited the most pronounced anti-inflammatory effects in vitro and demonstrated protective effects against colitis. Moreover, (R)-2,3-dihydroxy-isovalerate reinstated the protective effects of silibinin in mice with colitis under antibiotic exposure. These effects were primarily mediated via the targeting of the colonic GABA transporter 3 by (R)-2,3-dihydroxy-isovalerate. We further revealed that the retinoic acid receptor β and the retinoid-related orphan nuclear receptor γt may mediate the impact of silibinin-derived microbiota and (R)-2,3-dihydroxy-isovalerate on colitis. Additionally, the knockdown of colonic GABA transporter 3 diminished the impact of silibinin on the GABA transporter 3/retinoic acid receptor β/retinoid-related orphan nuclear receptor γt axis and colitis. Our findings highlight that (R)-2,3-dihydroxy-isovalerate, enriched from microbiota derived from silibinin, can target the GABA transporter 3/retinoic acid receptor β/retinoid-related orphan nuclear receptor γt axis, which is essential for anti-colitis properties of silibinin-regulated microbiota.
研究领域:
药理学
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微生物学
·
免疫学
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胃肠病学
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代谢组学
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分子生物学
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PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 21
·1-13
·
IF 2.8
Su Congxue,Tao Wenlong,Chen Lianchun,Che Haiyan,Wang Ruijuan,Fan Jun,Qin Xingliu,Chen Zhilin,Fang Liang
Orthorhombic olivine-structured LiTmRO 4 (R = Si, Ge) ceramics were synthesized using a solid-state reaction. Promising microwave dielectric properties of ε r = 8.18, τ f = 13.7 ppm/°C and a high-quality factor ( Q × f ) of 24,274 GHz for LiTmSiO 4 were obtained at 1130 °C, and ε r = 8.67, τ f = − 24.4 ppm/°C and Q × f = 19,231 GHz for LiTmGeO 4 were achieved at 1090 °C. According to the bond valence results, Tm 3+ and Ge 4+ presented a compressed state, but Li + exhibited a strong rattling state in LiTmGeO 4 , which led to a higher ε r than ε theo . The integrated effect of the rattling cations (Li + and Si 4+ ) and a compressed cation (Tm 3+ ) in LiTmSiO 4 resulted in a smaller positive deviation ∆ ε r . The larger packing fraction of LiTmSiO 4 contributed to a higher Q × f than that of LiTmGeO 4 . The R–O bond in both ceramics played a leading role in influencing Q × f according to the Phillips–Van Vechten–Levine chemical bond theory.
研究领域:
材料科学
·
化学
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高影响因子
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